The role of pharmacogenetics in the treatment of depression and anxiety disorders

Treatment-resistant depression in children and adolescents

Major depressive disorder (MDD) in children and adolescents is a significant health problem, causing profound impairments in social, academic, and family functioning and substantial morbidity and mortality. Up to 15% of children and adolescents suffer from MDD, and a proportion, around 30 to 40% of them, failed to respond to initial selective serotonin reuptake inhibitor (SSRI) treatment. The only evidence-based recommendation is medication switching to another SSRI and augmentation with cognitive behavioral therapy. Newly developing treatment, including ketamine, transcranial magnetic stimulation, psychotherapy other than cognitive behavioral therapy, and combined pharmacotherapy with other interventions, requires further longitudinal controlled trials regarding efficacy and safety in this vulnerable population.

Prognosis and Improved Outcomes in Major Depression: A Review

(Reprinted from Transl Psychiatry. 2019 Apr 3; 9(1):127. Open access; is licensed under a Creative Commons Attribution 4.0 International License).

Position statement of the European Psychiatric Association (EPA) on the value of antidepressants in the treatment of unipolar depression

This position statement will address in an evidence-based approach some of the important issues and controversies of current drug treatment of depression such as the efficacy of antidepressants, their effect on suicidality and their place in a complex psychiatric treatment strategy including psychotherapy. The efficacy of antidepressants is clinically relevant. The highest effect size was demonstrated for severe depression. Based on responder rates and based on double-blind placebo-controlled studies, the number needed to treat (NNT) is 5–7 for acute treatment and four for maintenance treatment. Monotherapy with one drug is often not sufficient and has to be followed by other antidepressants or by comedication/augmentation therapy approaches. Generally, antidepressants reduce suicidality, but under special conditions like young age or personality disorder, they can also increase suicidality. However, under the conditions of good clinical practice, the risk–benefit relationship of treatment with antidepressants can be judged as favourable also in this respect. The capacity of psychiatrists to individualise and optimise treatment decisions in terms of ‘the right drug/treatment for the right patient’ is still restricted since currently there are no sufficient powerful clinical or biological predictors which could help to achieve this goal. There is hope that in future pharmacogenetics will contribute significantly to a personalised treatment. With regard to plasma concentration, therapeutic drug monitoring (TDM) is a useful tool to optimize plasma levels therapeutic outcome. The ideal that all steps of clinical decision-making can be based on the strict rules of evidence-based medicine is far away from reality. Clinical experience so far still has a great impact.

Association Study of the Beta-Adrenergic Receptor Genetic Variant Gly389Arg and Fluoxetine Response in Major Depression

Background

Pharmacogenetics has proven role in the treatment of different illnesses. Patients with special genotypes may achieve a better response to a specific drug. On the other hand, genetic parameters markedly contribute to the development of major depressive disorder (MDD). The significance of adrenergic system compartments in cognition and behavior, and their role in etiology of depression denote that adrenergic receptors beta gene polymorphism(s) might also have an association with drug response. Thus this study aims to evaluate the association between β1AR gene polymorphisms, G1165C, Arg389Gly and response to fluoxetine in MDD patients.

Materials and Methods

Among different antidepressants, we focused on fluoxetine as it is prescribed frequently in MDD and belongs to one of the most efficient antidepressant categories with minimum side effects. MDD was diagnosed at study entry using DSM-IV criteria. One hundred and one new MDD patients were treated with fluoxetine for a period of 6 weeks. A 50% decrease in Hamilton Rating Scale for Depression (HRSD) was considered as response to treatment. Genotyping of G1165C polymorphism was performed by PCR-RFLP method.

Results

Results of the study indicated no significant relationship between β1AR polymorphism and the patient's response to fluoxetine neither at genotypic nor allelic level (P=0.568).

Conclusion

Our study did not support the hypothesis of involvement of β1AR Arg389Gly polymorphism and response to fluoxetine in MDD patients.

Prognosis and improved outcomes in major depression: a review

Treatment outcomes for major depressive disorder (MDD) need to be improved. Presently, no clinically relevant tools have been established for stratifying subgroups or predicting outcomes. This literature review sought to investigate factors closely linked to outcome and summarize existing and novel strategies for improvement. The results show that early recognition and treatment are crucial, as duration of untreated depression correlates with worse outcomes. Early improvement is associated with response and remission, while comorbidities prolong course of illness. Potential biomarkers have been explored, including hippocampal volumes, neuronal activity of the anterior cingulate cortex, and levels of brain-derived neurotrophic factor (BDNF) and central and peripheral inflammatory markers (e.g., translocator protein (TSPO), interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor alpha (TNFα)). However, their integration into routine clinical care has not yet been fully elucidated, and more research is needed in this regard. Genetic findings suggest that testing for CYP450 isoenzyme activity may improve treatment outcomes. Strategies such as managing risk factors, improving clinical trial methodology, and designing structured step-by-step treatments are also beneficial. Finally, drawing on existing guidelines, we outline a sequential treatment optimization paradigm for selecting first-, second-, and third-line treatments for acute and chronically ill patients. Well-established treatments such as electroconvulsive therapy (ECT) are clinically relevant for treatment-resistant populations, and novel transcranial stimulation methods such as theta-burst stimulation (TBS) and magnetic seizure therapy (MST) have shown promising results. Novel rapid-acting antidepressants, such as ketamine, may also constitute a paradigm shift in treatment optimization for MDD.

Gene-based analysis of genes related to neurotrophic pathway suggests association of BDNF and VEGFA with antidepressant treatment-response in depressed patients

It is well established that brain-derived neurotrophic factor (BDNF) signaling pathway plays a key role in the pathophysiology of major depressive disorder (MDD) and in therapeutic mechanisms of antidepressants. We aim to identify genetic vairiants related to MDD susceptibility and antidepressant therapeutic response by using gene-based association analysis with genes related to the neurotrophic pathway. The present study investigated the role of genetic variants in the 10 neurotrophic-related genes (BDNF, NGFR, NTRK2, MTOR, VEGFA, S100A10, SERPINE1, ARHGAP33, GSK3B, CREB1) in MDD susceptibility through a case-control (455 MDD patients and 2,998 healthy controls) study and in antidepressant efficacy (n = 455). Measures of antidepressant therapeutic efficacy were evaluated using the 21-item Hamilton Rating Scale for Depression. Our single-marker and gene-based analyses with ten genes related to the neurotrophic pathway identified 6 polymorphisms that reached a significant level (p-value < 5.0 × 10⁻³) in both meta- and mega-analyses in antidepressant therapeutic response. One polymorphism was mapped to BDNF and 5 other polymorphisms were mapped to VEGFA. For case-control association study, we found that all of these reported polymorphisms and genes did not reach a suggestive level. The present study supported a role of BDNF and VEGFA variants in MDD therapeutic response.

Optimization of Antidepressant use with Pharmacogenetic Strategies

BACKGROUND

The response rate in the pharmacological treatment of depression has been estimated to be around 50%, achieving a remission in symptomatology in only one third of the patients. Suboptimal prescription of antidepressants has been proposed as a significant explanatory factor for this therapeutic inefficacy. The use of pharmacogenetic testing might favor the optimization of pharmacotherapy in emotional disorders. However, its implementation in the clinical routine requires studies which prove its efficacy.

OBJECTIVE

The aim is to explore the clinical effects obtained by means of the personalization of antidepressant treatment derived from the pharmacogenetic profile of the individual.

METHOD

A sample of 291 patients under antidepressant treatment was selected, and these patients were genotyped for the most common polymorphisms of the CYP2D6, CYP2C9, CYP2C19 and CYP3A4/5 genes using RT-PCR and TaqMan® technology. 30 of them were subjected to psycho-affective assessment using the HDRS scale before and after a process of individualization of their psychopharmacological treatment in accordance with the genotype obtained.

RESULTS

70% of the individuals treated using the traditional criterion of trial-and-error were not taking the active ingredient most suited to their pharmacogenetic profile. The inclusion of this genetic information in the choice of drug and its dosage entailed a significant, progressive reduction in depressive symptomatology, with an efficacy ratio of 80% and a remission of the pathology in almost 30% of the cases.

CONCLUSION

These results suggest that the prescription of pharmacogenetic profile-based strategies has a positive effect on the therapeutic response to antidepressants.

Optimization of Antidepressant use with Pharmacogenetic Strategies

Background:

The response rate in the pharmacological treatment of depression has been estimated to be around 50%, achieving a remission in symptomatology in only one third of the patients. Suboptimal prescription of antidepressants has been proposed as a significant explanatory factor for this therapeutic inefficacy. The use of pharmacogenetic testing might favor the optimization of pharmacotherapy in emotional disorders. However, its implementation in the clinical routine requires studies which prove its efficacy.

Objective:

The aim is to explore the clinical effects obtained by means of the personalization of antidepressant treatment derived from the pharmacogenetic profile of the individual.

Method:

A sample of 291 patients under antidepressant treatment was selected, and these patients were genotyped for the most common polymorphisms of the CYP2D6, CYP2C9, CYP2C19 and CYP3A4/5 genes using RT-PCR and TaqMan® technology. 30 of them were subjected to psycho-affective assessment using the HDRS scale before and after a process of individualization of their psychopharmacological treatment in accordance with the genotype obtained.

Results:

70% of the individuals treated using the traditional criterion of trial-and-error were not taking the active ingredient most suited to their pharmacogenetic profile. The inclusion of this genetic information in the choice of drug and its dosage entailed a significant, progressive reduction in depressive symptomatology, with an efficacy ratio of 80% and a remission of the pathology in almost 30% of the cases.

Conclusion:

These results suggest that the prescription of pharmacogenetic profile-based strategies has a positive effect on the therapeutic response to antidepressants.

TPH-2 Polymorphisms Interact with Early Life Stress to Influence Response to Treatment with Antidepressant Drugs

BACKGROUND

Variation in genes implicated in monoamine neurotransmission may interact with environmental factors to influence antidepressant response. We aimed to determine how a range of single nucleotide polymorphisms in monoaminergic genes influence this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample. An initial study of monoaminergic coding region single nucleotide polymorphisms identified significant associations of TPH2 and HTR1B single nucleotide polymorphisms with treatment response that showed interactions with childhood and recent life stress, respectively (Xu et al., 2012).

METHODS

A total of 47 further single nucleotide polymorphisms in 17 candidate monoaminergic genes were genotyped in 281 Chinese Han patients with major depressive disorder. Response to 6 weeks' antidepressant treatment was determined by change in the 17-item Hamilton Depression Rating Scale score, and previous stressful events were evaluated by the Life Events Scale and Childhood Trauma Questionnaire-Short Form.

RESULTS

Three TPH2 single nucleotide polymorphisms (rs11178998, rs7963717, and rs2171363) were significantly associated with antidepressant response in this Chinese sample, as was a haplotype in TPH2 (rs2171363 and rs1487278). One of these, rs2171363, showed a significant interaction with childhood adversity in its association with antidepressant response.

CONCLUSIONS

These findings provide further evidence that variation in TPH2 is associated with antidepressant response and may also interact with childhood trauma to influence outcome of antidepressant treatment.

Major depressive disorder in older adults: benefits and hazards of prolonged treatment

Antidepressants have been shown to reduce the risk of depression recurrence in adults, justifying prolonged antidepressant maintenance therapy for most if not all patients. However, older depressed adults may be at increased risk for antidepressant adverse effects. This article discusses the benefits and hazards of continued treatment in elderly depressed patients, and indicates which patients should and should not receive maintenance phase antidepressants. Most clinical trials conducted so far suggest that prolonged antidepressant use in older adults is efficacious to reduce recurrence rates. The benefits of prolonged antidepressant use may not be restricted to preventing recurrence but also include preservation of overall well-being, social functioning, reduced mortality risk from medical disorders, and reduced risk of dementia. Although generally safe, the prolonged use of antidepressants has been associated with higher risk of osteopenia/osteoporosis (in particular the selective serotonin reuptake inhibitors) and cardiovascular toxicity (tricyclic antidepressants). Fewer data are available for special populations, like those with multiple medical comorbidities or those with dementia; thus, the benefits of prolonged antidepressant use are not clear in these individuals.

Pharmacogenetics and analgesic effects of antidepressants in chronic pain management

Antidepressants are widely administered to chronic pain patients, but there is large interindividual variability in their efficacy and adverse effect rates that may be attributed to genetic factors. Studies have attempted to determine the impact of genetic polymorphisms in enzymes and transporters that are involved in antidepressant pharmacokinetics, for example, cytochrome P450 and P-gp. The impacts of genetic polymorphisms in the targets of antidepressants, such as the serotonin receptor or transporter, the noradrenaline transporter and the COMT and monoamine oxydase enzymes, have also been described. This manuscript discusses the current knowledge of the influence of genetic factors on the plasma concentrations, efficacy and adverse effects of the major antidepressants used in pain management.

The effectiveness of integrative medicine interventions on pain and anxiety in cardiovascular inpatients: a practice-based research evaluation

BACKGROUND

Pain and anxiety occurring from cardiovascular disease are associated with long-term health risks. Integrative medicine (IM) therapies reduce pain and anxiety in small samples of hospitalized cardiovascular patients within randomized controlled trials; however, practice-based effectiveness research has been limited. The goal of the study is to evaluate the effectiveness of IM interventions (i.e., bodywork, mind-body and energy therapies, and traditional Chinese medicine) on pain and anxiety measures across a cardiovascular population.

METHODS

Retrospective data obtained from medical records identified patients with a cardiovascular ICD-9 code admitted to a large Midwestern hospital between 7/1/2009 and 12/31/2012. Outcomes were changes in patient-reported pain and anxiety, rated before and after IM treatments based on a numeric scale (0-10).

RESULTS

Of 57,295 hospital cardiovascular admissions, 6,589 (11.5%) included IM. After receiving IM therapy, patients averaged a 46.5% (p-value < 0.001) decrease in pain and a 54.8% (p-value < 0.001) decrease in anxiety. There was no difference between treatment modalities on pain reduction; however, mind-body and energy therapies (p-value < 0.01), traditional Chinese medicine (p-value < 0.05), and combination therapies (p-value < 0.01) were more effective at reducing anxiety than bodywork therapies. Each additional year of age reduced the odds of receiving any IM therapy by two percent (OR: 0.98, p-value < 0.01) and females had 96% (OR: 1.96, p-value < 0.01) higher odds of receiving any IM therapy compared to males.

CONCLUSIONS

Cardiovascular inpatients reported statistically significant decreases in pain and anxiety following care with adjunctive IM interventions. This study underscores the potential for future practice-based research to investigate the best approach for incorporating these therapies into an acute care setting such that IM therapies are most appropriately provided to patient populations.

Management of treatment-resistant depression in children and adolescents

Depression is a relatively common diagnosis in children and adolescents, and is associated with significant morbidity and suicidality in this population. Evidence-based treatment of the acute illness is imperative to try to prevent the development of treatment-resistant depression or other complications. In situations where response to acute treatment is inadequate, clinicians should first consider factors that may influence outcome, such as psychiatric or medical comorbidities, psychosocial stressors, and treatment noncompliance. Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for depression in children and adolescents. For treatment-resistant depression, a switch to an alternate SSRI is recommended before trials of other antidepressants. Psychotherapy, such as cognitive behavioral therapy or interpersonal therapy, may improve treatment response. More research is needed examining medication augmentation strategies for treatment-resistant depression in children and adolescents.

The Personalized Advantage Index: translating research on prediction into individualized treatment recommendations. A demonstration

Background

Advances in personalized medicine require the identification of variables that predict differential response to treatments as well as the development and refinement of methods to transform predictive information into actionable recommendations.

Objective

To illustrate and test a new method for integrating predictive information to aid in treatment selection, using data from a randomized treatment comparison.

Method

Data from a trial of antidepressant medications (N = 104) versus cognitive behavioral therapy (N = 50) for Major Depressive Disorder were used to produce predictions of post-treatment scores on the Hamilton Rating Scale for Depression (HRSD) in each of the two treatments for each of the 154 patients. The patient's own data were not used in the models that yielded these predictions. Five pre-randomization variables that predicted differential response (marital status, employment status, life events, comorbid personality disorder, and prior medication trials) were included in regression models, permitting the calculation of each patient's Personalized Advantage Index (PAI), in HRSD units.

Results

For 60% of the sample a clinically meaningful advantage (PAI≥3) was predicted for one of the treatments, relative to the other. When these patients were divided into those randomly assigned to their “Optimal” treatment versus those assigned to their “Non-optimal” treatment, outcomes in the former group were superior (d = 0.58, 95% CI .17—1.01).

Conclusions

This approach to treatment selection, implemented in the context of two equally effective treatments, yielded effects that, if obtained prospectively, would rival those routinely observed in comparisons of active versus control treatments.

Synergistic effect of 5-HT2A receptor gene and MAOA gene on the negative emotion of patients with depression

OBJECTIVE

To analyse the synergistic effect of polymorphism of the tandem repeat sequence u-VNTR of 5-hydroxytryptamine 2A (5-HT2A) receptor gene and monoamine oxidase A (MAOA) gene on the negative emotion in frontal lobe of patients with depression through functional magnetic resonance imaging (fMRI) technique.

METHODS

Functional magnetic resonance imaging scanning was performed for 72 patients with depression and 70 gender, age-matched healthy people with physical examination under negative emotion recognition task. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was adopted to analyse genotype. The superior, middle and inferior gyrus of bilateral frontal lobe was regarded as the brain region of interest, and then the difference of activation intensity in frontal lobe subregion between control groups and patient groups with different genotypes, and the interaction between the two kinds of polymorphism were compared.

RESULTS

The activation intensity in right frontal middle gyrus of patients with CC genotype increased obviously compared with TT and TC genotype patient groups and TT genotype control group (P<0·01); the activation intensity in right frontal inferior gyrus of patients with CC genotype increased obviously compared with TT and TC genotype patient groups and control groups (P<0·01); the activation intensity in right frontal middle gyrus and left frontal inferior gyrus of patients with MAOA high-activity genotype increased obviously compared with patient and control groups with MAOA low-activity genotype (P<0·01). In sum, there existed synergistic effect of the two genotypes on the activation abnormality of negative emotion recognition in right frontal middle gyrus (F = 6·18, P = 0·029). The negative activation in right frontal middle gyrus of patients with CC+H genotypes increased most obviously (P<0·05).

CONCLUSION

The frontal abnormality of patients with depression had certain 5-HT genetic basis, and 5-HT2A receptor CC allele and MAOA-H genotype had synergistic effect on the activity abnormality when recognizing negative emotion in right frontal middle gyrus of patients with depression.

Role of allelic variants of FK506-binding protein 51 (FKBP5) gene in the development of anxiety disorders

BACKGROUND

Anxiety disorders exhibit remarkably high rates of comorbidity with major depressive disorder (MDD). Mood and anxiety disorders are considered stress-related diseases. Genetic variations in the co-chaperone FK506-binding protein 51, FKBP5, which modulates the function of glucocorticoid receptors, have been associated with an increased risk for the development of posttraumatic stress disorder, but data regarding its role in MDD are controversial. The aims of this study were to clarify the role of the FKBP5 gene in depression and anxiety disorders through a case-control study and an association study with personality traits using the Temperament and Character Inventory (TCI) in healthy subjects.

METHODS

Six hundred fifty-seven MDD patients, with or without an anxiety disorder in comorbidity, and 462 healthy volunteers were enrolled in the study. Two hundred fifty-six controls agreed to fill out the TCI.

RESULTS

The results showed that the T allele of rs1360780 was more frequent among the patients affected by MDD with a comorbidity of anxiety disorders, compared to those without (P < .001). Among the controls, we found that the T allele more often exhibited personality traits associated with an increased vulnerability to anxiety.

CONCLUSIONS

These results support the hypothesis that allelic variants of FKBP5 are a risk factor for anxiety disorders. The identification of genetic variants involved in anxiety may have implications for the optimization of therapeutic interventions.

The impact of Cytochrome P450 CYP1A2, CYP2C9, CYP2C19 and CYP2D6 genes on suicide attempt and suicide risk-a European multicentre study on treatment-resistant major depressive disorder

Recently published data have reported associations between cytochrome P450 metabolizer status and suicidality. The aim of our study was to investigate the role of genetic polymorphisms of the cytochrome P450 genes on suicide risk and/or a personal history of suicide attempts. Two hundred forty-three major depressive disorder patients were collected in the context of a European multicentre resistant depression study and treated with antidepressants at adequate doses for at least 4 weeks. Suicidality was assessed using the Mini International Neuropsychiatric Interview and the Hamilton Rating Scale for Depression (HAM-D). Treatment response was defined as HAM-D ≤ 17 and remission as HAM-D ≤ 7 after 4 weeks of treatment with antidepressants at adequate dose. Genotyping was performed for all relevant variations of the CYP1A2 gene (*1A, *1F, *1C, *1 J, *1 K), the CYP2C9 gene (*2, *3), the CYP2C19 gene (*2, *17) and the CYP2D6 gene (*3, *4, *5, *6, *9, *19, *XN). No association between both suicide risk and personal history of suicide attempts, and the above mentioned metabolic profiles were found after multiple testing corrections. In conclusion, the investigated cytochrome gene polymorphisms do not seem to be associated with suicide risk and/or a personal history of suicide attempts, though methodological and sample size limitations do not allow definitive conclusions.

Association between serotonin transporter-linked polymorphic region and escitalopram antidepressant treatment response in Korean patients with major depressive disorder

OBJECTIVE

Various studies have shown that short (s)/long (l) polymorphisms of the serotonin transporter-linked polymorphic region (5-HTTLPR) might predict treatment outcome to selective serotonin reuptake inhibitors. The purpose of this study was to evaluate the association between 5-HTTLPR and clinical response to escitalopram treatment in Korean subjects with major depressive disorder.

METHODS

One hundred and fifteen Korean patients diagnosed with major depressive disorder were evaluated during 8 weeks of escitalopram treatment at a dose of 5-20 mg/day. Patients were genotyped for 5-HTTLPR using polymerase chain reaction. Clinical symptoms were evaluated by the 21-item Hamilton Depression Rating (HAMD-21) scale during the 8 weeks of treatment.

RESULTS

Therapeutic response to antidepressant escitalopram was better in s allele carriers (ss, sl) than in l allele homozygotes (ll) at 8 weeks of treatment (OR = 6.24, p = 0.026). The proportion of s allele carriers in responders was higher than that in non-responders (96.6 vs. 85.7%). The percentile decline in HAMD-21 in s allele carriers (59.86 ± 3.23%) was larger than that in HAMD-21 in l allele homozygotes (43.13 ± 11.49%; p = 0.029). However, 5-HTTLPR genotypes were not significantly associated with remission (p > 0.05).

CONCLUSIONS

Our results show that treatment response to escitalopram at 8 weeks was moderated by 5-HTTLPR, with better response rates for s allele carriers than for l allele homozygotes. Although the role of 5-HTTLPR as a definite predictor of selective serotonin reuptake inhibitor treatment response cannot be confirmed from current results, they do suggest a trend for better response in s allele carriers.

Influence of genetic polymorphisms in the glutamatergic and GABAergic systems and their interactions with environmental stressors on antidepressant response

Aim: To investigate the role of genetic polymorphisms in glutamatergic and GABAergic genes and their interactions with environmental stressors in antidepressant response. Methods: A set of 114 SNPs of 34 glutamatergic and GABAergic genes, mainly in promoter and coding regions, were genotyped in 281 Chinese Han major depressive disorder patients. The 17-item Hamilton Depression Rating Scale was used to evaluate the symptom severity and therapeutic efficacy. Childhood Trauma Questionnaire and Life Events Scale were used for assessing early-onset and recent stressful life events, respectively. Results: The single SNPs rs1954787 (GRIK4), rs1992647 (GABRA6), rs10036156 (GABRP) and rs3810651 (GABRQ) were significantly associated with antidepressant response, as were haplotypes in GRIK4 and GABRP genes. A genetic interaction between rs11542313 (GAD1), rs13303344 (GABRD) and rs2256882 (GABRE) was identified as impacting therapeutic response. SNPs in GRIA3 demonstrated interactions with early-onset adverse events and recent negative life stress that influence treatment outcome. Conclusion: Genetic polymorphisms in the glutamatergic and GABAergic systems and certain genetic interactions, as well as gene–environment interactions, are associated with antidepressant response.

Original submitted 9 July 2012; Revision submitted 1 January 2013

Imaging genetics: implications for research on variable antidepressant drug response

Genetic variation of SLC6A4, HTR1A, MAOA, COMT and BDNF has been associated with depression, variable antidepressant drug responses as well as impacts on brain regions of emotion processing that are modulated by antidepressants. Pharmacogenetic studies are using psychometric outcome measures of drug response and are hampered by small effect sizes that might be overcome by the use of intermediate endophenotypes of drug response, which are suggested by imaging studies. Such an approach will not only tighten the relationship between genes and drug response, but also yield new insights into the neurobiology of depression and individual drug responses. This article provides a comprehensive overview of pharmacogenetic, imaging genetics and drug response studies, utilizing imaging techniques within the context of antidepressive drug therapy.

The drugs don't work? antidepressants and the current and future pharmacological management of depression

Depression is a potentially life-threatening disorder affecting millions of people across the globe. It is a huge burden to both the individual and society, costing over £9 billion in 2000 alone: the World Health Organisation (WHO) cited it as the third leading cause of global disability in 2004 (first in the developed world), and project it will be the leading cause by 2030. The serendipitous discovery of antidepressants has revolutionized both our understanding and management of depression: however, their efficacy in the treatment of depression has long been debated and recently been brought very much into the public limelight by a controversial publication by Kirsch, in which the role of placebo response in antidepressant efficacy trials is highlighted. Whilst antidepressants offer benefits in both the short and long term, important problems persist such as intolerability, delayed therapeutic onset, limited efficacy in milder depression and the existence of treatment-resistant depression.

Epistasis between 5-HTTLPR and ADRA2B polymorphisms influences attentional bias for emotional information in healthy volunteers

Individual differences in emotional processing are likely to contribute to vulnerability and resilience to emotional disorders such as depression and anxiety. Genetic variation is known to contribute to these differences but they remain incompletely understood. The serotonin transporter (5-HTTLPR) and α2B-adrenergic autoreceptor (ADRA2B) insertion/deletion polymorphisms impact on two separate but interacting monaminergic signalling mechanisms that have been implicated in both emotional processing and emotional disorders. Recent studies suggest that the 5-HTTLPR s allele is associated with a negative attentional bias and an increased risk of emotional disorders. However, such complex behavioural traits are likely to exhibit polygenicity, including epistasis. This study examined the contribution of the 5-HTTLPR and ADRA2B insertion/deletion polymorphisms to attentional biases for aversive information in 94 healthy male volunteers and found evidence of a significant epistatic effect (p<0.001). Specifically, in the presence of the 5-HTTLPR s allele, the attentional bias for aversive information was attenuated by possession of the ADRA2B deletion variant whereas in the absence of the s allele, the bias was enhanced. These data identify a cognitive mechanism linking genotype-dependent serotonergic and noradrenergic signalling that is likely to have implications for the development of cognitive markers for depression/anxiety as well as therapeutic drug effects and personalized approaches to treatment.

Neurotrophins role in depression neurobiology: a review of basic and clinical evidence

Depression is a neuropsychiatric disorder affecting a huge percentage of the active population especially in developed countries. Research has devoted much of its attention to this problematic and many drugs have been developed and are currently prescribed to treat this pathology. Yet, many patients are refractory to the available therapeutic drugs, which mainly act by increasing the levels of the monoamines serotonin and noradrenaline in the synaptic cleft. Even in the cases antidepressants are effective, it is usually observed a delay of a few weeks between the onset of treatment and remission of the clinical symptoms. Additionally, many of these patients who show remission with antidepressant therapy present a relapse of depression upon treatment cessation. Thus research has focused on other possible molecular targets, besides monoamines, underlying depression. Both basic and clinical evidence indicates that depression is associated with several structural and neurochemical changes where the levels of neurotrophins, particularly of brain-derived neurotrophic factor (BDNF), are altered. Antidepressants, as well as other therapeutic strategies, seem to restore these levels. Neuronal atrophy, mostly detected in limbic structures that regulate mood and cognition, like the hippocampus, is observed in depressed patients and in animal behavioural paradigms for depression. Moreover, chronic antidepressant treatment enhances adult hippocampal neurogenesis, supporting the notion that this event underlies antidepressants effects. Here we review some of the preclinical and clinical studies, aimed at disclosing the role of neurotrophins in the pathophysiological mechanisms of depression and the mode of action of antidepressants, which favour the neurotrophic/neurogenic hypothesis.

European Group for the Study of Resistant Depression (GSRD)--where have we gone so far: review of clinical and genetic findings

The primary objective of this review is to give an overview of the main findings of the European multicenter project "Patterns of Treatment Resistance and Switching Strategies in Affective Disorder", performed by the Group for the Study of Resistant Depression (GSRD). The aim was to study methodological issues, operational criteria, clinical characteristics, and genetic variables associated with treatment resistant depression (TRD), that is failure to reach response after at least two consecutive adequate antidepressant trials. The primary findings of clinical variables associated with treatment resistance include comorbid anxiety disorders as well as non-response to the first antidepressant received lifetime. Although there is a plethora of hints in textbooks that switching the mechanism of action should be obtained in case of nonresponse to one medication, the results of the GSRD challenge this notion by demonstrating in retrospective and prospective evaluations that staying on the same antidepressant mechanism of action for a longer time is more beneficial than switching, however, when switching is an option there is no benefit to switch across class. The GSRD candidate gene studies found that metabolism status according to cytochrome P450 gene polymorphisms may not be helpful to predict response and remission rates to antidepressants. Significant associations with MDD and antidepressant treatment response were found for COMT SNPs. Investigating the impact of COMT on suicidal behaviour, we found a significant association with suicide risk in MDD patients not responding to antidepressant treatment, but not in responders. Further significant associations with treatment response phenotypes were found with BDNF, 5HTR2A and CREB1. Additional investigated candidate genes were DTNBP1, 5HT1A, PTGS2, GRIK4 and GNB3.

The acute effects of kava and oxazepam on anxiety, mood, neurocognition; and genetic correlates: a randomized, placebo-controlled, double-blind study

RATIONALE

Kava (Piper methysticum) is a psychotropic plant medicine with history of cultural and medicinal use. We conducted a study comparing the acute neurocognitive, anxiolytic, and thymoleptic effects of a medicinal dose of kava to a benzodiazepine and explored for the first time specific genetic polymorphisms, which may affect the psychotropic activity of phytomedicines or benzodiazepines.

METHODS

Twenty-two moderately anxious adults aged between 18 and 65 years were randomized to receive an acute dose of kava (180 mg of kavalactones), oxazepam (30 mg), and placebo 1 week apart in a crossover design trial.

RESULTS

After exposure to cognitive tasks, a significant interaction was revealed between conditions on State-Trait Anxiety Inventory-State anxiety (p = 0.046, partial ŋ² = 0.14). In the oxazepam condition, there was a significant reduction in anxiety (p = 0.035), whereas there was no change in anxiety in the kava condition, and there was an increase in anxiety in the placebo condition. An increase in Bond-Lader "calmness" (p = 0.002) also occurred for the oxazepam condition. Kava was found to have no negative effect on cognition, whereas a reduction in alertness (p < 0.001) occurred in the oxazepam condition. Genetic analyses provide tentative evidence that noradrenaline (SLC6A2) transporter polymorphisms may have an effect on response to kava.

CONCLUSION

Acute "medicinal level" doses of this particular kava cultivar in naive users do not provide anxiolytic activity, although the phytomedicine also appears to have no negative effects on cognition.

Anxiety and depression are independent predictors of quality of life of patients with chronic musculoskeletal pain

We examined the relative impact of baseline anxiety, depression and fear of movement on health related quality of life at 12-month follow-up after a multidisciplinary pain management programme. One hundred and eleven patients who had chronic musculoskeletal pain (mean age 45 years, 65% women) attended during 2003–2005 a multidisciplinary three-phase pain management programme with a total time frame of six to seven months, totalling 19 days. The Beck Anxiety Inventory was used to rate anxiety, the Beck Depression Inventory depression, the Tampa Scale of Kinesiophobia fear of movement. The generic 15D questionnaire was used to assess health related quality of life. Baseline data were collected at admission, follow-up data at 12 months. Mean health related quality of life increased significantly from baseline to 12-month follow-up. Anxiety at baseline predicted significant negative change in the health related quality of life, depression predicted significant positive change in the health related quality of life. Fear of movement did not predict any significant change in the health related quality of life. We concluded that patients with chronic musculoskeletal pain and mild to moderate depression benefit from a multidisciplinary pain management programme in contrast to anxious patients. The findings imply further research with bigger sample sizes, other than HRQoL outcome measures as well as with other groups of patients.

Influence and interaction of genetic polymorphisms in the serotonin system and life stress on antidepressant drug response

Variation in genes implicated in serotonin neurotransmission may interact with environmental factors to influence antidepressant response. We aimed to determine how a range of polymorphisms in serotonergic genes determine this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample. In total, 14 single nucleotide polymorphisms (SNPs) in coding regions of 10 serotonergic genes (HTR1A, HTR1B, HTR1D, HTR2A, HTR3A, HTR3C, HTR3D, HTR3E, HTR5A and TPH2) were genotyped in 308 Chinese Han patients with major depressive disorder. Response to 6 weeks' antidepressant treatment was determined by change in the 17-item Hamilton Depression Rating Scale (HDRS-17) score, and previous stressful events were evaluated by the Life Events Scale (LES) and Childhood Trauma Questionnaire-Short Form (CTQ-SF). Two 5-HT1B receptor SNPs (rs6296 and rs6298) and one tryptophan hydroxylase2 (rs7305115) SNP were significantly associated with antidepressant response in this Chinese sample, as was a haplotype in TPH2 (rs7305115 and rs4290270). A gene-gene interaction on antidepressant response was found between SNPs in HTR1B, HTR3A and HTR5A in female subjects. The HTR1B SNPs demonstrated interaction with recent stress, while that for TPH2 interacted with childhood trauma to influence antidepressant response.

Is switching antidepressants following early nonresponse more beneficial in acute-phase treatment of depression?: a randomized open-label trial

RATIONALE

Treatment guidelines for major depressive disorder (MDD) recommend a continuous use of antidepressants for several weeks, while recent meta-analyses indicate that antidepressant efficacy starts to appear within 2 weeks and early treatment nonresponse is a predictor of subsequent nonresponse.

OBJECTIVES

We prospectively compared 8-week outcomes between switching antidepressants and maintaining the same antidepressant in early nonresponders, to generate a hypothesis on possible benefits of early switching strategy.

METHOD

Patients with MDD without any treatment history for the current episode were included. When subjects failed to show an early response (i.e., ≥20% improvement in the Montgomery-Åsberg Depression Rating Scale (MADRS)) to the initial treatment with sertraline 50mg at week 2, they were randomly divided into two groups; in the Continuing group, sertraline was titrated at 50-100mg, whereas sertraline was switched to paroxetine 20-40 mg in the Switching group. A primary outcome measure was a response rate (i.e., ≥50% improvement in the MADRS) at week 8.

RESULTS

Among 132 subjects, 41 subjects showed early nonresponse. The Switching group (n=20) showed a higher rate of responders than the Continuing group (n=21) (75% vs. 19%: p=0.002). Further, the Switching group was also superior in the rate of remitters (total score of ≤10 in the MADRS) (60% vs. 14%: p=0.004) and continuous changes in the MADRS (19.0 vs. 7.5: p<0.001).

CONCLUSIONS

Our preliminary findings suggest that patients with MDD who fail to show early response to an initial antidepressant may derive benefits from the early switching antidepressants in the acute-phase treatment of depression.

Treatment-resistant depression in adolescents: review and updates on clinical management

Treatment-resistant depression (TRD) in adolescents is prevalent and impairing. We here review the definition, prevalence, clinical significance, risk factors, and management of TRD in adolescents. Risk factors associated with TRD include characteristics of depression (severity, level of hopelessness, and suicidal ideation), psychiatric and medical comorbidities, environmental factors (family conflict, maternal depression, and history of abuse), and pharmacokinetics and other biomarkers. Management options include review of the adequacy of the initial treatment, re-assessment for the above-noted factors that might predispose to treatment resistance, switching antidepressants, and augmentation with medication or psychotherapy. Other modalities, such as electroconvulsive therapy, vagal nerve stimulation, and repetitive transcranial magnetic stimulation, are also reviewed.

The genetic blueprint of major depressive disorder: contributions of imaging genetics studies

OBJECTIVES

To review neuroimaging intermediate phenotypes of MDD and their relation to genetic risk variants.

METHODS

A systematic literature search of peer-reviewed English language articels using PubMed ( www.pubmed.org ) was performed.

RESULTS

Comprehensive evidence on the influence of serotonergic genes (SLC6A4, HTR1A, MAOA, TPH2) and BDNF on the following neural intermediate phenotypes is displayed: amygdala reactivity, coupling of amygdala-anterior cingulate cortex (ACC) activity, ACC volume, hippocampal volume and serotonin receptor 1A (5-HT1A) binding potential (BP).

CONCLUSIONS

Intermediate phenotypes may bridge the gap between genotype and phenotype by reducing the impreciseness of psychiatric phenotypes and yield more insights into the underlying biology.

Sexual dysfunction during treatment with serotonergic and noradrenergic antidepressants: clinical description and the role of the 5-HTTLPR

OBJECTIVES

Sexual dysfunction (SD) is a frequently reported side-effect of antidepressant treatment, particularly of selective serotonin reuptake inhibitors (SSRIs). In the multicentre clinical and pharmacogenetic GENDEP study (Genome-based Therapeutic Drugs for Depression), the effect of the serotonin transporter gene promoter polymorphism 5-HTTLPR on sexual function was investigated during treatment with escitalopram (SSRI) and nortriptyline (tricyclic antidepressant).

METHODS

A total of 494 subjects with an episode of DSM-IV major depression were randomly assigned to treatment with escitalopram or nortriptyline. Over 12 weeks, depressive symptoms and SD were measured weekly with the Montgomery-Asberg Depression Rating Scale, the Antidepressant Side-Effect Checklist, the UKU Side Effect Rating Scale, and the Sexual Functioning Questionnaire.

RESULTS

The incidence of reported SD after 12 weeks of treatment was relatively low, and did not differ significantly between antidepressants (14.9% escitalopram, 19.7% nortriptyline). There was no significant interaction between the 5-HTTLPR and antidepressant on SD. Improvement in depressive symptoms and younger age were both associated with lower SD. The effect of age on SD may have been moderated by the 5-HTTLPR.

CONCLUSIONS

In GENDEP, rates of reported SD during treatment were lower than those described in previous reports. There was no apparent effect of the 5-HTTLPR on the observed decline in SD.

Influence and interaction of genetic polymorphisms in catecholamine neurotransmitter systems and early life stress on antidepressant drug response

BACKGROUND

Catecholamine neurotransmission plays an important role in major depression. Variation in genes implicated in the synthesis and signal transduction of catecholamines (norepinephrine and dopamine) may interact with environmental factors to affect the outcome of antidepressant treatment. We aimed to determine how a range of polymorphisms in noradrenergic and dopaminergic genes influence this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample.

METHODS

In a sample of 308 Chinese Han patients with major depressive disorder, 13 single nucleotide polymorphisms (SNPs) in coding regions of six genes (MAOA, SLC6A2, TH, COMT, DRD2, DRD3) with minor allele frequencies >5% were successfully genotyped from an initial series of 35 SNPs in 11 candidate genes associated with catecholamine neurotransmission. The responses to 6 weeks' treatment with antidepressant drugs was determined by changes in the 17-item Hamilton Depression Rating Scale (HAMD-17) score, and previous stressful events were evaluated by the Life Events Scale (LES) and Childhood Trauma Questionnaire-Short Form (CTQ-SF). Single SNP and haplotype associations with treatment response were analysed by UNPHASED 3.0.13, gene-gene interactions were analysed by generalized multifactor dimensionality reduction (GMDR) and gene-environment interactions by logistic regression.

RESULTS

A haplotype in MAOA (rs1137070 and rs6323) was significantly associated with antidepressant response in the total group, the nonSSRI subgroup and the female subgroup. Two haplotypes in COMT (involving rs4633, rs4818 and rs769224) were significantly associated with antidepressant response in the nonSSRI subgroup. The SLC6A2 SNPs interacted with childhood trauma to influence antidepressant response.

CONCLUSIONS

A haplotype in MAOA and two haplotypes in COMT are found to be associated with antidepressant treatment response in this sample. Stressors in early life may interact with polymorphisms in SLC6A2 to influence response to antidepressant treatment.

Strategies to achieve clinical effectiveness: refining existing therapies and pursuing emerging targets

BACKGROUND

Clinical effectiveness reflects a balance between efficacy and tolerability as well as patient satisfaction and overall improvement in quality of life and function. This is of particular importance when considering the long term use of antidepressant therapies for relapse prevention.

METHODS

The purpose of this review is to explore methods to enhance the modest efficacy and effectiveness outcomes reported with current antidepressant strategies. Two strategies are addressed: a) Doing better with existing treatments and b) pursuing novel targets beyond the monoamine system for new antidepressant drug development.

RESULTS

In the first instance, it is important to consider the balance between antidepressant efficacy and tolerability for individual patients and also be aware of evidence supporting superiority of one agent over others. Both sequential and concurrent combination therapies with existing antidepressants are also reviewed. The second approach involves a review of emerging novel pharmacological treatments based on biomarker research. Unique targets where antidepressant treatments appear effective include the melatonergic, glutamatergic, neurotrophic, cytokine, and neuropeptide systems.

CONCLUSIONS

While agomelatine represents an example of a clinically available antidepressant that targets melatonin receptors, drugs that act on other candidate systems are still in the development phase.

Association between tryptophan hydroxylase-2 genotype and the antidepressant effect of citalopram and paroxetine on immobility time in the forced swim test in mice

Tryptophan hydroxylase-2 (TPH2) is the rate limiting enzyme of serotonin synthesis in the brain. The 1473G allele of the C1473G polymorphism in mTPH2 gene is associated with reduced enzyme activity and serotonin synthesis rate in the mouse brain. Here, the influence of the 1473G allele on the antidepressant effect of selective serotonin reuptake inhibitors (SSRIs), citalopram (2.5 or 5.0mg/kg) and paroxetine (5.0 or 10.0mg/kg), in the forced swim test was studied using B6-1473G and B6-1473C congenic mouse lines with the 1473G (decreased TPH2 activity) or 1473C (normal TPH2 activity) alleles, respectively, transferred to the genome of C57BL/6 mouse strain. Paroxetine (5.0 or 10.0mg/kg) and citalopram (2.5 or 5.0mg/kg) decreased immobility time in B6-1473C mice, while both doses of paroxetine and 2.5mg/kg of citaloprame did not alter immobility time in B6-1473G mice. However, 5.0mg/kg of citalopram reduced immobility in B6-1473G mice. The results provided genetic evidence of moderate association between 1473G allele and reduced sensitivity to SSRIs in mice.

The double edged sword of neural plasticity: increasing serotonin levels leads to both greater vulnerability to depression and improved capacity to recover

Major depression is a chronic, recurring and potentially life-threatening illness that affects up to 10% of the population worldwide. Pharmacological and genetic studies highlight the serotonergic system as being a key player in the disorder. However, despite drugs designed to boost serotonin transmission represent the first line of therapy for depression, the role of this system still remains elusive. Here, I propose a new theoretical framework, the undirected susceptibility to change model, potentially accounting for the experimental and clinical results concerning the role of this neurotransmitter in depression. Since the capacity of the individual to change its physiology and behavior according to the environment is dependent on neural plasticity which, in turn, is controlled by serotonin, I assume that changes in the levels of serotonin affect the sensitivity to the environment. Consequently, the undirected susceptibility to change model predicts that an increase of serotonin levels, for instance induced through selective serotonin reuptake inhibitor (SSRI) administration, does not affect mood per se, but--acting as a catalyzer--enhances neural plasticity and, thus, the effects of the environment on mood. However, since the environment can be either supportive or adverse, its effects can be beneficial or detrimental. Therefore enhancing the serotonin system can increase the likelihood both of developing the psychopathology and recovering from it. This model, on the one hand, suggests an explanation for the limited SSRI efficacy described in clinical studies and allows apparently contradictory data to be reconciled; on the other, it describes neural plasticity as a double edged sword that, according to the quality of the environment, may have either positive or negative consequences.

PCLO rs2522833 modulates HPA system response to antidepressant treatment in major depressive disorder

Variant rs2522833 of the Piccolo-encoding gene PCLO has recently been found to be associated with major depressive disorder (MDD). PCLO encodes a presynaptic cytomatrix protein which influences monoamine neurotransmitter release. Piccolo could therefore play an important role in treatment response to antidepressant therapy and the improvement of alterations in HPA system reactivity. We investigated the influence of the coding variant rs2522833 in the PCLO gene on treatment response in 205 in-patients with unipolar depression. Treatment response was measured (1) at the level of psychopathology using the Hamilton Depression Rating Scale (HAMD) and (2) with the combined dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, which is a refined tool for showing dysregulation of the hypothalamic-pituitary-adrenocortical (HPA) system, a neurobiological finding in depression. While we did not find an association between variation in PCLO and HAMD scores, HPA dysregulation was less pronounced in carriers of the AA genotype than in carriers of one or two C alleles. HPA activity of individuals with the AA genotype only marginally changed during 4-wk antidepressant treatment, whereas C allele carriers showed a higher hormonal secretion at admission than carriers of the AA genotype but lower responsivity to the Dex/CRH challenge after 4 wk. Our results point to a moderating role of PCLO SNP rs2522833 on HPA regulation during antidepressant treatment, which may represent a neurobiological feature of stability of clinical response.

Juvenile stress attenuates the dorsal hippocampal postsynaptic 5-HT1A receptor function in adult rats

RATIONALE

Traumatic events in early life are associated with an increased risk of psychiatric diseases in adulthood. 5-hydroxytryptamine (5-HT)(1A) receptors play a pivotal role in the 5-HTergic mechanisms associated with the etiology of stress-related disorders.

OBJECTIVE

The goal of the present study was to investigate whether juvenile stress influences emotional control via postsynaptic 5-HT(1A) receptor in the hippocampus and amygdala using contextual fear conditioning test in adult rats.

METHODS

The rats were subjected to aversive footshock (FS) during the third week of the postnatal period (3wFS group). During the postadolescent period (10-14 weeks postnatal), experiments were performed.

RESULTS

The systemic administration of the 5-HT(1A) receptor agonist R-(+)-8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) (0.2 mg/kg, i.p.) attenuated the freezing behavior in the non-FS group, but not in the 3wFS group. The bilateral local injection of 8-OH-DPAT (1 μg/side) into the amygdala decreased the freezing behavior in the non-FS group and the 3wFS group. However, the local injection of 8-OH-DPAT (1 μg/side) into the hippocampus decreased the freezing behavior in the non-FS group, but not in the 3wFS group. In a 5-HT(1A) receptor binding study, the Bmax of the 3wFS group decreased in the dorsal hippocampus, but not the amygdala in comparison with the non-FS group.

CONCLUSIONS

The juvenile stress attenuated the hippocampal postsynaptic 5-HT(1A) receptor function in context-dependent conditioned fear.

Kava: a comprehensive review of efficacy, safety, and psychopharmacology

OVERVIEW

Kava (Piper methysticum) is a South Pacific psychotropic plant medicine that has anxiolytic activity. This effect is achieved from modulation of GABA activity via alteration of lipid membrane structure and sodium channel function, monoamine oxidase B inhibition, and noradrenaline and dopamine re-uptake inhibition. Kava is available over the counter in jurisdictions such as the USA, Australia and New Zealand. Due to this, a review of efficacy, safety and clinical recommendations is advised.

OBJECTIVE

To conduct a comprehensive review of kava, in respect to efficacy, psychopharmacology, and safety, and to provide clinical recommendations for use in psychiatry to treat generalized anxiety disorder (GAD).

METHODS

A review was conducted using the electronic databases MEDLINE, CINAHL, PsycINFO and the Cochrane Library during mid 2010 of search terms relating to kava and GAD. A subsequent forward search was conducted of key papers using Web of Science cited reference search.

RESULTS

The current weight of evidence supports the use of kava in treatment of anxiety with a significant result occurring in four out of six studies reviewed (mean Cohen's d = 1.1). Safety issues should however be considered. Use of traditional water soluble extracts of the rhizome (root) of appropriate kava cultivars is advised, in addition to avoidance of use with alcohol and caution with other psychotropic medications. Avoidance of high doses if driving or operating heavy machinery should be mandatory. For regular users routine liver function tests are advised.

CONCLUSIONS

While current evidence supports kava for generalized anxiety, more studies are required to assess comparative efficacy and safety (on the liver, cognition, driving, and sexual effects) versus established pharmaceutical comparators.

The role of FKBP5 in cancer aetiology and chemoresistance

FK506 binding protein 51 (FKBP51, also called FKBP5) belongs to a family of immunophilins, FK506 binding proteins (FKBPs). Members of this family are targets for drugs such as rapamycin and cyclosporine. Although FKBP5 shares characteristics with other FKBPs, it also has unique features, especially its role in the regulation of multiple signalling pathways and in tumourigenesis and chemoresistance. In this review, we will focus on the recently discovered role of FKBP5 in cancer aetiology and response to antineoplastic therapy.

Pharmacogenomics of suicidal events

Pharmacogenomic studies of antidepressant treatment-emergent suicidal events in depressed patients report associations with polymorphisms in genes involved in transcription (CREB1), neuroprotection (BDNF and NTRK2), glutamatergic and noradrenergic neurotransmission (GRIA3, GRIK2 and ADRA2A), the stress and inflammatory responses (FKBP5 and IL28RA), and the synthesis of glycoproteins (PAPLN). Nearly all of the reported events in these studies were modest one-time increases in suicidal ideation. In 3231 unique subjects across six studies, 424 (13.1%) patients showed increases in suicidal ideation, eight (0.25%) attempted suicide and four (0.12%) completed suicide. Systems related to most of these genes have also been implicated in studies of suicidal behavior irrespective of treatment. Future pharmacogenomic studies should target events that are clinically significant, related clinical phenotypes of response and medication side effects, and biological pathways that are involved in these outcomes in order to improve treatment approaches.

Pharmacogenetics and psychoactive drug therapy: ready for the patient?

Psychiatry is one of the most promising areas for bringing pharmacogenomics to the patient. Psychiatric disorders such as depression and schizophrenia contribute significantly to worldwide morbidity and mortality. Forecasts rank depression second only to ischemic heart disease by 2020. In depression and schizophrenia, 30% to 50% of all patients do not respond sufficiently to the initial treatment regime. Genetic variability has been demonstrated to play an important role in the response to pharmacotherapy. Most data are available with regard to polymorphisms in the genes coding for drug-metabolizing enzymes and recommendations for the choice of personalized dosages based on genotyping results are available. Clinical outcome, in particular adverse effects, has been shown to correlate with the results from genotyping. Incorporating pharmacogenomics into clinical practice has, however, been slow and it is still not clear in which clinical situations genotyping should be performed and what the benefit of such procedures could be beyond therapeutic drug monitoring. Additionally, many studies in psychiatry focus on genetic variation in candidate genes of drug targets. However, despite promising reports, no clear recommendation can be given at present to perform such testing in clinical use.

Dose-effect study of Gelsemium sempervirens in high dilutions on anxiety-related responses in mice

INTRODUCTION

This study was designed to investigate the putative anxiolytic-like activity of ultra-low doses of Gelsemium sempervirens (G. sempervirens), produced according to the homeopathic pharmacopeia.

METHODS

Five different centesimal (C) dilutions of G. sempervirens (4C, 5C, 7C, 9C and 30C), the drug buspirone (5 mg/kg) and solvent vehicle were delivered intraperitoneally to groups of ICR-CD1 mice over a period of 9 days. The behavioral effects were assessed in the open-field (OF) and light-dark (LD) tests in blind and randomized fashion.

RESULTS

Most G. sempervirens dilutions did not affect the total distance traveled in the OF (only the 5C had an almost significant stimulatory effect on this parameter), indicating that the medicine caused no sedation effects or unspecific changes in locomotor activity. In the same test, buspirone induced a slight but statistically significant decrease in locomotion. G. sempervirens showed little stimulatory activity on the time spent and distance traveled in the central zone of the OF, but this effect was not statistically significant. In the LD test, G. sempervirens increased the % time spent in the light compartment, an indicator of anxiolytic-like activity, with a statistically significant effect using the 5C, 9C and 30C dilutions. These effects were comparable to those of buspirone. The number of transitions between the compartments of the LD test markedly increased with G. sempervirens 5C, 9C and 30C dilutions.

CONCLUSION

The overall pattern of results provides evidence that G. sempervirens acts on the emotional reactivity of mice, and that its anxiolytic-like effects are apparent, with a non-linear relationship, even at high dilutions.